Methods for fabrication of intercalated lithium batteries

ABSTRACT

A method for fabricating intercalated lithium batteries in open air deposits a thin dense layer of amorphous solid-state lithium boride electrolyte directly onto a negative electrode via flame spray pyrolysis. In one embodiment, the negative electrode is attached to a prefabricated positive electrode via hot pressing (embossing), thus forming an intercalated lithium battery. The method significantly improves upon current methods of fabricating thin film solid state batteries by permitting fabrication without the aid of a controlled environment, thereby allowing for significantly cheaper fabrication than prior batch methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority based on U.S. Provisional PatentApplication Ser. No. 61/611,139 filed Mar. 15, 2012 and titled “Open AirMethod for the Fabrication of Intercalated Lithium Batteries,” thedisclosure of which is incorporated herein by this reference.

BACKGROUND

This invention relates to an improved process for manufacturing lithiumbatteries, and in particular a process that may be employed in an openenvironment.

Batteries are comprised of a positive and a negative electrode separatedby an ionically conductive, but electrically insulating, electrolyte.Secondary batteries are further defined by reversible electrochemicalreactions. Secondary batteries come in a wide variety of types andsizes, but are generally defined by the mobile ion. Thus, lithiumsecondary batteries typically rely upon conduction of the mobile lithiumion, Li⁺.

Typically, liquid electrolyte lithium batteries are fabricated undervacuum conditions because both the electrolyte, such as LiPF₆, and themetallic lithium negative electrode react violently with moisture in theambient atmosphere. Solid state lithium batteries are also manufacturedunder vacuum conditions due to two important factors. First, the mostpopular electrolyte and electrode materials for solid state batteriesalso react with moisture. In fact, many thin film batteries use lithiummetal as the negative electrode and Lithium cobaltite (LiCoO₂) as thepositive electrode. Second, solid state batteries depend on an amorphousthin film electrolyte, for which there are few known methods offabrication.

Previous studies of thin film lithium batteries often focused on the useof lithium phosphorus oxynitride (LiPON) as the electrolyte. Therelatively high ionic conductivity and stability in contact withmetallic lithium make LiPON a popular choice. Ionic conductivity,however, is heavily dependant on the nitrogen content and thus islimited to vacuum deposition methods.

Two alternate electrolyte materials, lithium metaborate (LiBO2) andlithium sulfide (Li2S) glasses, have also been found to be good lithiumion conductors. Although they provide good conductivity, sulfide glassestend to be unstable both in contact with lithium metal and underatmospheric conditions. LiBO2 electrolytes have also been found to beunstable with lithium metal but do not typically have similar problemsunder atmospheric conditions. It was also been found that phosphorousadditives, such as P2O5, can further increase the ionic conductivity.

Similar to liquid electrolyte batteries, most solid state lithiumbatteries utilize metallic lithium as a negative electrode. Metalliclithium is popular because it supplies a high electrochemical potentialand thus open circuit voltage (OCV). Although toxic, corrosive andflammable, lithium metal can be manipulated under a controlledenvironment.

Alternatively, thin film batteries can be developed as an intercalated,or rocking chair, battery. The intercalated battery is a specific typeof secondary lithium battery in which both the anode and cathode areformed with intercalation compounds rather than metallic lithium. Inthis case, the elemental lithium is impregnated, or intercalated, in anoxide rather than applied directly. The lithium ions then move back andforth between interstitial sites as the battery is charged anddischarged. While this often reduces the open circuit voltage (OCV) ofthe cell, intercalated batteries have found niche applications due toimproved safety characteristics and power-to-weight ratios.

More recently, lithium impregnated materials have been investigated aspotential electrode materials. In 1995 it was shown that the hightemperature phase of LiCoO2 shows good stability and reversibility.Oriented vanadium (III) oxide has also been shown to be a potentialelectrode material.

For solid electrolytes, amorphous thin films are typically preferredbecause grain boundaries tend to inhibit lithium ion movement within theelectrolyte. Because lithium is propagated in solid state ionicconductors by an interstitial method, amorphous or nanocrystallinematerials show consistently higher ionic conductivity than do theircrystalline counterparts. Unfortunately, only select techniques arecapable of depositing thin amorphous films. To this point, thedeposition of dense, amorphous, lithium-containing films has often usedvacuum or controlled environment processes.

In the last several years, numerous thin film lithium batteries havebeen developed and commercialized. Thin films are usually considered tobe less than 10 microns thick. The Handbook of Thin-Film DepositionProcesses and Techniques (Noyes Pubs. 1988; Schuegraf, K. K. editor)provides a broad review of thin-film deposition techniques. Thesetechnologies include chemical vapor deposition, pulsed laser deposition,e-beam evaporation and DC/RF sputtering.

Some of the first thin film lithium batteries were developed based on anamorphous lithium phosphosilicate electrolyte. Unfortunately thiselectrolyte was unstable in contact with metallic lithium and littleprogress was made until the advent of lithium phosphorus oxynitride(LiPON). LiPON electrolytes were found to be stable up to 5.5V versuslithium metal, which encouraged the development of experimentalprototypes. Lithium boride (LiBO2) and lithium sulfide (Li2S) glasseswere also found to be good lithium ion conductors. While providingexcellent conductivity, sulfide glasses were shown to be unstable bothin contact with lithium metal and under atmospheric conditions. Incontrast, LiBO2 electrolytes were found to be unstable with lithiummetal but did not have similar problems under atmospheric conditions.

A variety of intercalated electrodes were developed to replace lithiummetal. In 1995 it was shown that the high temperature phase of LiCoO₂shows good stability and reversibility. More recently oriented Vanadium(III) Oxide was shown to be a potential electrode material.

Solid state intercalated lithium batteries are typically manufactured ina controlled environment using thin film deposition methods such aschemical vapor deposition, pulsed laser deposition, DC/RF magnetronsputtering or e-beam evaporation. Such time and energy intensive methodsare required due to the material choices and the difficulty in producingamorphous lithium ion conductors. However, thin film intercalatedlithium batteries could be produced much more cheaply and efficiently ifthin film, amorphous electrolytes could be developed in the ambientatmosphere.

SUMMARY

The present disclosure provides a method for manufacturing anintercalated lithium battery in an open environment. In contrast toprior methods, the present method uses combustion chemical vapordeposition (“CCVD”), also known as flame spray pyrolysis, to depositLiBO₂ electrolytes. The method takes advantage of the fact that LiBO₂films deposited between 850° C. and 1000° C. are dense, amorphous andstoichiometrically precise. Because CCVD does not require a controlledatmosphere, the present method can be performed in open air. Whencombined with intercalated electrodes, a solid state lithium battery maybe fabricated entirely in the ambient atmosphere. Ultimately, thisshould reduce fabrication costs and increase process speeds by allowingbattery manufacturers to switch from a batch process to a continuousrolling process.

The present method includes a multi-step method for the fabrication ofintercalated lithium batteries in open air. First, a negative currentcollector and negative electrode (or anode) assembly is prefabricated.Next, an amorphous, dense lithium boride electrolyte is deposited atopthe negative electrode via flame spray pyrolysis. The thickness of thisfilm is typically between 100 nm and 50 μm and is sufficientlycontinuous to prevent contact between the positive and negativeelectrodes.

Next, the positive electrode (or cathode) is deposited on top of thelithium boride electrolyte to form a negative current collector/negativeelectrode/electrolyte/positive electrode assembly. Finally, a positivecurrent collector is deposited atop the positive electrode assembly toform a working lithium battery having the cross-sectional structurenegative current collector/negative electrode/electrolyte/positiveelectrode/positive current collector. Alternatively, the negativeelectrode/negative current collector assembly may also be prefabricatedand bonded directly to the positive current collector/positiveelectrode/electrolyte assembly. Of special note is that all parts ofthis process are developed in the ambient atmosphere.

Specifically, according to the present method, an intercalated lithiumbattery is produced in an ambient atmosphere by first providing asubstrate to serve as the negative electrode. The substrate has at leastone surface that may be coated. The substrate may be formed from avariety of materials, such as LiCoO₂, the principal requirements beingthat the substrate be electrically conductive and capable of holding orstoring lithium, because the battery stores lithium on both the anodeand the cathode, depending on the state of charge of the battery.

An amorphous layer of LiBO₂ (lithium metaborate) is formed by CCVD. Theprocess begins by mixing a solution of a combustible fluid (typically analcohol solution, such as ethanol methanol, or isopropanol) withfluid-soluble lithium and boron compounds. Examples of such compoundsare LiNO₃ and BCl₃. The lithium and boron compounds dissolve in thefluid to form a reagent mixture. The reagent mixture is sprayed througha nozzle to a liquid spray containing the reagent mixture. The spraypasses through a flame to combust the reagent mixture, thereby formingheated lithium metaborate.

The lithium metaborate deposits onto the substrate at a temperaturebetween 750 C and 1100 C, where it cools to form an amorphous lithiummetaborate coating on the substrate. The substrate is removed from theflame following deposition, and adhered to a positive electrode, forexample by hot pressing. The result is an intercalated lithium battery.Alternatively, the positive electrode can be directly deposited atop theelectrolyte by any thin film deposition method, such as CCVD, CVD orsputtering.

There are several alternative ways of producing the battery. Forexample, the order in which the positive and negative electrodes aredeposited may be reversed. The positive electrode may be made of one ofseveral common positive electrode materials, such as is V₂O₅, LiCoO₂,manganese spinel, lithiated transition metal oxide compounds, LiNiO₂ orlithium manganese oxide. The negative electrode may be any of severalcommon electrodes, such that the standard potential of the negativeelectrode is sufficiently less than that of the positive electrode.Common negative electrodes are LiCoO₂, carbon black, graphite, graphene,carbon nanotubes, silicon carbide or disordered carbon compounds.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will be apparentfrom reference to the following Detailed Description taken inconjunction with the accompanying Drawings, in which:

FIG. 1 depicts a schematic diagram of a deposition apparatus accordingto one embodiment;

FIG. 2 depicts a schematic diagram of a portion of the depositionapparatus of FIG. 1;

FIG. 3 depicts a schematic view of the steps of the present processaccording to one embodiment;

FIG. 4 is a photograph of a Au/Si/Au/LiCoO₂/LiBO₂/V₂O₅/Au test cell;

FIG. 5 is an energy dispersive X-ray spectrograph of the test cell ofFIG. 4;

FIG. 6 shows chronoamperometry curves of the test cell of FIG. 4;

FIG. 7 is a self-discharge curve of the cell of FIG. 4;

FIGS. 8a and 8b depict two SEM micrographs of LiBO₂ films developed viaCCVD at fabrication temperatures of 500° C.;

FIGS. 8c and 8d depict two SEM micrographs of LiBO₂ films developed viaCCVD at fabrication temperatures of 750° C.;

FIGS. 8e and 8f depict two SEM micrographs of LiBO₂ films developed viaCCVD at fabrication temperatures of 900° C.;

FIG. 9 depicts a first set of Fourier transform infrared spectroscopy(“FTIR”) scans of LiBO₂ films fabricated at 500° C., 750° C. and 900°C.;

FIG. 10 depicts a second set of FTIR scans of LiBO₂ films fabricated at500° C., 750° C. and 900° C.;

FIG. 11 depicts a schematic of the equivalent circuit used to model theimpedance spectroscopy results presented in FIG. 12.

FIG. 12 depicts a characteristic impedance spectrograph of a LiBO₂ filmat room temperature.

DETAILED DESCRIPTION

According to one embodiment, the present method deposits an amorphousfilm of LiBO₂ (lithium metaborate) as an electrolyte directly onto anactive electrode substrate, such as LiCoO₃ or V₂O₅. The method may usecombustion chemical vapor deposition (“CCVD”), sometimes known as FlameSpray Pyrolysis. The film may be deposited at different temperatures.

As depicted in FIG. 1, a deposition apparatus 10 includes supply tanks12 that pass combustion fuel gases through flow controllers 14 to acombustion device 16, which burns the supply gases. At the same time, apump 20 pumps a reagent mixture 22 through the burning flame 24. Thereagent mixture is ignited, thereby converting the precursors into LiBO₂in flight. The material then lands on the substrate 30 and cools,thereby forming a thin film 32.

FIG. 2 depicts a closer view of the deposition process. As can be seen,the supply gases pass through outlets 34 and are ignited to form theflame 24. The reagent mixture is formed by mixing a solution of acombustible fluid (typically an alcohol having small amounts of water,such as ethanol, methanol, or isopropanol) with fluid-soluble lithium(LiNo₃) and boron (BCl₃) compounds. The lithium and boron compoundsdissolve in the fluid to form a reagent mixture. The reagent mixture issprayed through the nozzle 38 to form a liquid spray containing thereagent mixture. Atomized droplets 40 of the reagent mixture passthrough the flame 24, thereby forming heated lithium metaboratedroplets. The heated droplets are then deposited onto a substrate 30 toform a thin film 32 of LiBO₂. When the substrate is an active electrode,such as LiCoO₂ or graphite, the LiBO₂ acts as an electrolyte.

When lithium metaborate deposits onto the substrate at a temperaturebetween 750 C and 1100 C, the resulting film may be amorphous. Thesubstrate is removed from the flame following deposition, and the LiBO₂coated side of the assembly is adhered to a positive electrode, forexample by hot pressing, CCVD or chemical vapor deposition. The resultis an intercalated lithium battery.

FIG. 3 schematically depicts the steps used to make the intercalatedbattery according to one embodiment of the present methods. The methodbegins with an N-type silicon wafer 50. The wafer 50 is etched (Step 1),and gold deposited over the entire surface of the wafer. A layer 52 ofLiCoO2 is then deposited on the wafer 50 (Step 3) using CCVD, and a LiBOlayer 54 deposited on top of the LiCoO2 (Step 4), as previouslydiscussed with respect to FIGS. 1 and 2. A layer 56 of V2O5 is depositedonto the wafer (Step 5), following which a gold current collector 58 isdeposited (Step 6), completing the basic battery construction steps.

FIG. 4 is an optical photograph of the Au/Si/Au/LiCoO₂/LiBO₂/V₂O₅/Autest cell. The test cell measured approximately 5 mm×5 mm×0.5 mm, 97% ofwhich was inactive substrate. The thin film nature of the cell allows itto be deposited on a variety of substrates for maximum utility.

FIG. 5 is an energy dispersive X-ray spectrograph of the test cell.Sharp peaks associated with polycrystalline cobalt can be seen atapproximately 0.8 keV and 6.9 keV. Similarly, peaks associated withpolycrystalline vanadium are evident at 4.9 and 5.4 keV. Lithium doesnot show up as it is too small to be imaged effectively by EDXS whilethe boron is contained in an amorphous film, rendering it invisible toX-ray analysis.

Initial Performance Curves

FIG. 6 shows chronoamperometry curves of theAu/Si/Au/LiCoO2/LiBO₂/V2O5/Au test cell. For these measurements, thecurrent was held at +1 μA for 150 s and subsequently reversed to −1 μAfor 50 s. FIG. 7 is a self-discharge curve of the test cell shown inFIG. 4. For these measurements, the current was held at +10 nA for 2500s to charge and the switched to open circuit for 5500 s. The voltagedrop over this period indicates that the leakage current is non-zero.

Examples

Molar quantities of precursor components of Lithium nitrate (LiNO₃) andBoron trichloride (BCl₃) were measured and dissolved in ethanol tocreate a precursor solution of 0.025M. The solution pH was raised frompH 3 to pH 7 with ammonium hydroxide prior to deposition. Prior toutilization in the CCVD system (the deposition apparatus 10schematically depicted in FIG. 1), the solution was placed in anultrasonic bath for 20 minutes to ensure complete dissolution of soluteand to eliminate agglomeration.

The solution was then deposited onto substrates using the depositionapparatus 10. During deposition, a magnetic stir bar was used to preventsolute particles from settling. Oxygen and methane in a 4:1 ratioprovided the feed gas for the CCVD flame 24. The deposition time washeld constant at 20 minutes for each sample. The deposition temperaturewas changed to produce multiple unique LiBO₂ films. The resulting LiBO₂films were thus fabricated entirely in an ambient, or open air,environment. Each film was extensively characterized by scanningelectron microscopy (SEM), impedance spectroscopy and Fourier transforminfrared spectroscopy (FTIR).

Following deposition, the thin film cells were imaged with ScanningElectron Microscopy (SEM) and evaluated with impedance spectroscopy. SEMimages were taken using a Hitachi 4100 Field Emission Microscope. A thincarbon coating was deposited via RF sputtering prior to introductioninto the vacuum chamber in order to reduce charging of the substrateduring imaging. FIGS. 8 a-f present planar and cross-sectional SEMimages of LiBO₂ thin films. The cell encompassed an active area of 2mm×2 mm with a LiBO₂ electrolyte thickness of approximately 1 μm. FIG. 8(a-f) are SEM micrographs of the LiBO₂ films developed via CCVD atfabrication temperatures of 500° C. (FIGS. 8 a,b), 750° C. (FIGS. 8 c,d)and 900° C. (FIGS. 8 e,f).

The thin films of LiBO₂ were characterized using IR reflectance spectra.Infrared reflectance measurements were recorded with a Bomem DA3spectrometer with an evacuated chamber and an MCT detector. A siliconcarbide glowbar served as the beam source with a CaF2 beam splitter. Thevariable reflection angle was fixed at 30°, yielding a wavelengthresolution of 4 cm⁻¹. Each IR spectra was compiled from 100 scans of thesample.

The IR reflectance peaks for LiBO₂ films deposited at 500° C., 750° C.and 900° C. are displayed in FIGS. 9 and 10. Strong peaks at wavelengthsof 1420 cm⁻¹, 1440 cm⁻¹ and 1590 cm⁻¹ are associated with thecrystalline phase of α-LiBO₂. In FIG. 9, the films deposited at 750° C.show both a strong double peak at 1420 cm⁻¹ and 1440 cm⁻¹ and asecondary peak at 1590 cm⁻¹ indicating a large presence of crystallineα-LiBO₂. Films deposited at 500° C. showed similar peaks at 1420 cm⁻¹,1440 cm⁻¹ and 1590 cm⁻¹, but with less intensity. This may be a resultof a thinner film due to differences in deposition rates. Conversely,films deposited at 900° C. showed none of these peaks and more clearlyreflected the spectrum for amorphous LiBO₂.

Changes in film thickness may be attributable to changes in the workingdistance during fabrication. To minimize the number of independentvariables, flame conditions were held constant throughout the filmfabrication process. As such, fabrication temperature was adjusted bymoving the substrate nearer to or farther from the flame. Because thedeposition geometry is roughly conical, deposition closer to the spraynozzle will result in a slightly higher deposition rate. It should benoted that the total change in position, between the nearest andfurthest deposition positions, totaled 35 mm or roughly 10.3% of thetotal nozzle to substrate distance.

For electrochemical measurements, the LiBO₂ films were deposited atop agold coated n-type silicon wafer. Silicon substrates were prepared byetching the native SiBO₂ layer in a 5% HF bath for 20 minutes. Oncecleaned, substrates were immediately covered with gold on both sidesusing DC sputtering. Electrical measurements prior to LiBO₂ depositionconfirmed a negligible resistance vertically through the Si wafer. Thewafer was then diced and cleaned for deposition of the electrolyte.After LiBO₂ deposition, a matching Au electrode was sputtered atop theelectrolyte for electrochemical testing.

LiBO₂ thin films were characterized electrochemically in air viaimpedance spectroscopy. Electrical contacts were made by placing thesymmetric cell between two spring loaded platinum mesh electrodes. Acomputer interface controlling a Gamry PCI4-750 Potentiostat board andcontroller board collected data over a frequency range from 100 kHz to 1mHz using a two-electrode configuration.

Impedance measurements of LiBO₂ films formed at 500° C. and 750° C.displayed a small real resistance of less than 1 ohm with an inductivecomponent. This type of impedance spectra reflects a short circuitwithin the system, indicating that these layers were not sufficientlydense to prevent the positive electrode from touching the negative.Conversely, impedance spectrographs of LiBO₂ films deposited at 900° C.showed a single large interfacial polarization loop peaking near 7943 Hzwith very little ohmic resistance.

FIG. 12 is a characteristic impedance spectrograph of the LiBO₂ film atroom temperature. This film was fabricated at 900° C. Because theimpedance curve did not cross the real axis at low frequencies due tothe onset of Warburg impedance, a simplified equivalent circuitsimulation was used to estimate the polarization resistance, Rp. FIG. 11presents a schematic of the equivalent circuit.

At room temperature, a total cell resistance of 1.3e5 ohms was recordedfor a LiBO₂ cell of dimensions of 2 mm×1.5 mm×1.5 μm. The experimentalconductivity of 3.84e-8 S/cm falls within published values for LiBO₂ of3.18e-8 to 7.78e-7. The wide range in LiBO₂ ionic conductivity is areflection of differing lithium contents implying that the LiBO₂ filmdeveloped here may be slightly lithium deficient. While the ionicconductivity of LiBO₂ falls below that for LiPON electrolytes of 2.3e-6S/cm, the higher electrical resistivity 10-12 for LiBO₂ vs. 10-8-10-9for LiPON, makes it a viable electrolyte material. A higher electricalresistivity means that thinner films can be used without shorting thesystem.

Thus, the present methods may be used to fabricate thin films of LiBO₂using CCVD. At 500° C. and 750° C., the films may be porous andpolycrystalline, but films deposited at 900° C. were amorphous anddense. The films were imaged with SEM, characterized with IR adsorptionspectroscopy and electrochemically evaluated with impedancespectroscopy. LiBO₂ films developed at 900° C. showed a conductivity of3.84e-8S/cm, well within the published range for this material

In contrast to alternative methods for LiBO₂ fabrication, these filmswere developed in an open air environment. Two advantages of this methodversus vacuum or controlled environment methods are cost and speed. Byworking in open air, up-front plant construction costs may besignificantly reduced.

Most thin film batteries are more expensive than their liquidelectrolyte counterparts because the fabrication process incursnon-trivial costs. Maintaining a high vacuum during fabrication is atime and energy intensive proposition. Multiple vacuum pumps, specialtymaterials and relatively small chamber sizes are needed to minimizeoutgassing and maintain a controlled environment. Moving from vacuumdeposition to open air fabrication reduces these problems therebysignificantly lowering the upfront plant costs. Because raw materialscan make up 70-80% of the cost of a battery, few businesses areinterested in such a low margin product. However, by significantlycutting the up-front costs, a much higher return on investment can beseen.

Furthermore, LiBO₂ electrolytes fabricated by CCVD have been developedat a deposition rate of roughly 400 Å/minute, more than two orders ofmagnitude faster than the average rates for CVD, PLD or sputteringsystems. When pumpdown and system prep times are included, thedeposition rate for traditional thin film methods falls even further. Onthe other hand, CCVD has already been developed as a continuousthroughput system. By switching from a batch process to a continuousdeposition process, output can be significantly increased, therebyimproving the return on investment.

Therefore, the present method for fabricating an intercalated lithiumbattery without the assistance of a controlled environment comprises thefollowing steps: (a) providing a substrate to serve as the negativeelectrode having at least one surface to be coated; (b) selecting areagent and a carrier medium and mixing together said reagent and saidcarrier medium to form a reagent mixture, the reagent being selectedsuch that at least a portion of the reagent forms a lithium boridecoating; (c) spraying the reagent mixture through a nozzle to forms aliquid spray containing the reagent mixture; (d) passing said spray orvapor through a flame such that the reagent mixture is combusted; e)locating said substrate in a zone located relative to said liquid sprayor vapor such that the surface temperature of the substrate is between850° C. and 1000° C.; (e) removing said substrate from the flamefollowing deposition; f) adhering a positive electrode to the coatedsurface of the substrate via hot pressing to form an intercalatedlithium battery. The negative electrode may be a graphite film orLithium cobaltite. The positive electrode may be a vanadium oxide film.The order in which the positive and negative electrodes are depositedmay be switched.

Furthermore, the deposition method used may be combustion chemical vapordeposition. The carrier medium may be a liquid organic solvent. Thereagent may be a gas, a vapor, or a liquid and said carrier is a gas, avapor, or a liquid. The coating may comprise a combination of vapordeposited and spray pyrolysis deposited film of said reagent. Thecoating may also comprised spray pyrolysis deposited film of thereagent. The coating may be less than about 100 microns in thickness, orless than about 1 microns in thickness. The substrate may be heatedpredominately by the heat of combustion produced by combusting saidreagent mixture, or by a secondary heat source. The deposition andirradiation typically occurs at a pressure between 10 torr and 10,000torr.

The present methods have several advantages over prior methods. Althoughembodiments of the present methods have been described, variousmodifications and changes may be made by those skilled in the artwithout departing from the spirit and scope of the invention.

The invention claimed is:
 1. A method for fabricating an intercalatedlithium battery without the assistance of a controlled environmentcomprising the steps of: (a) providing a substrate to serve as thenegative electrode having at least one surface to be coated; (b) forminga layer of amorphous LiBO₂ (lithium metaborate) directly on the at leastone surface of the substrate by: mixing a solution of a combustiblefluid with fluid-soluble lithium and boron compounds to dissolve thecompounds in the fluid to form a reagent mixture; spraying the reagentmixture through a nozzle to form a liquid spray containing the reagentmixture; passing the spray through a flame to combust the reagentmixture, thereby forming heated lithium metaborate; depositing thelithium metaborate onto the substrate at a temperature between 750° Cand 1100° C to form an amorphous lithium metaborate coating on thesubstrate; (c) removing the coated substrate from the flame followingdeposition; and (d) directly adhering a positive electrode configured toaccept lithium ions to the layer of amorphous LiBO₂ to form anintercalated lithium battery.
 2. The method of claim 1 wherein thelithium metaborate is deposited onto the substrate at a temperature ofbetween 850° C. and 1000° C.
 3. The method of claim 1 wherein thenegative electrode is made of graphite or graphene.
 4. The method ofclaim 1 wherein the positive electrode is made of vanadium oxide.
 5. Themethod of claim 1 wherein the negative electrode is made of LiCoO₂. 6.The method of claim 1 wherein the positive electrode is adhered by hotpressing, chemical vapor deposition, RF Sputtering, DC Sputtering orPulsed Laser Deposition.
 7. The method of claim 1 wherein thecombustible fluid comprises an alcohol.
 8. The method of claim 1 whereinthe combustible fluid comprises an organic solvent.
 9. The method ofclaim 1 where the fluid soluble lithium compound is LiNO₃.
 10. Themethod of claim 1 where the fluid soluble boron compound is BCl₃. 11.The method of claim 1 where the positive electrode comprises at leastone of V2O5, LiCoO2, Manganese spinel compounds, LiNiO2, LithiumManganese oxide, or Lithiated transition metal oxides.
 12. The method ofclaim 1 where the negative electrode comprises at least one of LiCoO2,carbon black, graphite, graphene, carbon nanotubes, silicon carbide ordisordered carbon compounds.
 13. A method for fabricating anintercalated lithium battery without the assistance of a controlledenvironment comprising the steps of: (a) providing a substrate to serveas the positive electrode having at least one surface to be coated; (b)forming a layer of amorphous LiBO₂ (lithium metaborate) directly on theat least one surface of the substrate by: mixing a solution of acombustible fluid with fluid-soluble lithium and boron compounds todissolve the compounds in the fluid to form a reagent mixture; sprayingthe reagent mixture through a nozzle to form a liquid spray containingthe reagent mixture; passing the spray through a flame to combust thereagent mixture, thereby forming heated lithium metaborate; depositingthe lithium metaborate onto the substrate at a temperature between 750°C and 1100° C to form an amorphous lithium metaborate coating on thesubstrate; (c) removing the coated substrate from the flame followingdeposition; and (d) directly adhering a negative electrode configured toaccept lithium ions to the layer of amorphous LiBO₂ to form anintercalated lithium battery.
 14. The method of claim 13 wherein thelithium metaborate is deposited onto the substrate at a temperature ofbetween 850° C and 1000° C.
 15. The method of claim 13 wherein thenegative electrode is adhered by hot pressing, chemical vapordeposition, RF Sputtering, DC Sputtering or Pulsed Laser Deposition. 16.The method of claim 13 wherein the combustible fluid comprises at leastone of an alcohol or an organic solvent.
 17. The method of claim 13where the positive electrode comprises at least one of V205, LiCoO,Manganese spinel compounds, LiNiO₂, Lithium Manganese oxide, orLithiated transition metal oxides.
 18. The method of claim 13 where thenegative electrode comprises at least one of LiCoO₂, carbon black,graphite, graphene, carbon nanotubes, silicon carbide or disorderedcarbon compounds.